Aerosol aging and concentrating drum and method

ABSTRACT

A system with a rotatable drum and an exposure device configured to age and concentrate aerosol particles by simulating operational conditions. The system includes the rotatable drum; a port connected to the drum, an impactor with vacuum nozzles, the exposure device, and optionally an outlet port when the port is solely an inlet port. The port delivers the aerosol particles into the drum with the nozzles withdrawing air to increase the concentration of the particles. After aging and concentrating, evacuating the aerosol particles directly from the drum into at least one of an exposure chamber or a testing apparatus.

This application is a divisional application of U.S. patent applicationSer. No. 15/723,448 filed on Oct. 3, 2017 and claims benefit of U.S.Patent Application Ser. No. 62/403,524 filed on Oct. 3, 2016 and U.S.Patent Application Ser. No. 62/428,883 filed on Dec. 1, 2016, theentireties of which are incorporated by reference.

I. FIELD OF INVENTION

The present invention relates to systems, methods, and computer programproducts for an aerosol concentrating apparatus for use with aerosolaging drum, in particular for simulating operational conditions.

II. SUMMARY OF THE INVENTION

An embodiment of the invention provides an aerosol concentratingapparatus for use with an aerosol aging drum, where the aerosolconcentrating apparatus includes an outer housing, an aerosol inlet tubeconnected to the outer housing, and an extraction tube connected to theouter housing. An axle connected to the outer housing is axiallycentered within the outer housing, where the axle is formed from porousmaterial. An inner housing is connected to the axle, such that the axleis axially centered within the inner housing, and such that the innerhousing is adapted to spin about the axle within the outer housing toseparate aerosol particles by size. Aerosol particles below a firstthreshold size are forced out of the aerosol concentrating apparatusthrough the axle; and, aerosol particles between the first thresholdsize and a second threshold size are suspended within the inner housing.

Another embodiment provides a method of concentrating aerosol with anaerosol concentrating apparatus for use with an aerosol aging drum.Aerosol particles are released into an outer housing of the aerosolconcentrating apparatus through an aerosol inlet tube connected to theouter housing. An inner housing inside of the outer housing rotates toseparate the aerosol particles by size, such that the inner housingrotates around a porous central axle inside of the outer housing.Aerosol particles below a first threshold size are extracted through theporous central axle. Aerosol particles between the first threshold sizeand a second threshold size are suspended within the inner housing.

Yet another embodiment of the invention provides a method for aerosolaging and concentrating for simulating operational conditions whereaerosol particles are injected into an inlet port of a rotating drum.Air from the rotating drum is expelled via a nozzle to concentrate theaerosol particles within the drum; and, the inlet port and the nozzleare closed when a desired aerosol concentration is reached. The aerosolparticles are exposed to at least one environmental condition; and, theaerosol particles are evacuated from the rotating drum after an agingperiod. The aerosol particles can be evacuated directly from therotating drum into an exposure chamber and/or a testing apparatus.

In still yet another embodiment, a system for aerosol aging andconcentrating for simulating operational conditions includes a rotatabledrum and an inlet port connected to the rotatable drum that receivesaerosol particles. A nozzle connected to the rotatable drum expels airfrom the rotatable drum to concentrate the aerosol particles within therotatable drum. An exposure device exposes the aerosol particles to oneor more environmental conditions. An outlet port connected to therotatable drum evacuates the aerosol particles directly from therotatable drum into an exposure chamber and/or a testing apparatus.

III. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention is described with reference to the accompanyingdrawings. In the drawings, like reference numbers indicate identical orfunctionally similar elements.

FIGS. 1A-2 illustrate the underlying mathematical steps used in anaerosol centrifuge design according to an embodiment of the invention.FIG. 1F illustrates how some of the variables related to the system.

FIG. 3 is a graph illustrating radius of an aerosol aging drum versusrotational speed according to an embodiment of the invention.

FIG. 4 is a graph illustrating radius of an aerosol aging drum versusrotational speed according to an embodiment of the invention.

FIG. 5 is a graph illustrating radius of an aerosol aging drum versusrotational speed according to an embodiment of the invention.

FIG. 6 is a graph illustrating radius of an aerosol aging drum versusrotational speed according to an embodiment of the invention.

FIG. 7 illustrates an aerosol concentrating apparatus according to anembodiment of the invention.

FIG. 8 is a flow diagram illustrating a method for using an aerosolconcentrating apparatus according to an embodiment of the invention.

FIG. 9 illustrates a top left perspective view of a system for anaerosol aging and concentrating drum for simulating operationalconditions according to an embodiment of the invention.

FIG. 10 illustrates a top view of the system illustrated in FIG. 9.

FIG. 11 illustrates a front view of the system illustrated in FIG. 9.

FIG. 12 illustrates a left side view of the system illustrated in FIG.9.

FIG. 13 illustrates a right side view of the system illustrated in FIG.9.

FIG. 14 illustrates a top right perspective view of the systemillustrated in FIG. 9.

FIG. 15 illustrates the geometry of the rotating drum aerosolconcentrator according to an embodiment of the invention.

FIG. 16 illustrates the geometry of the rotating drum aerosolconcentrator according to an embodiment of the invention.

FIG. 17 illustrates the geometry of the rotating drum aerosolconcentrator according to an embodiment of the invention.

FIG. 18 illustrates the geometry of the rotating drum aerosolconcentrator according to an embodiment of the invention.

FIG. 19 illustrates the geometry of the rotating drum aerosolconcentrator according to an embodiment of the invention.

FIG. 20 illustrates a system of aerosol aging and concentrating forsimulating operational conditions according to an embodiment of theinvention.

FIG. 21 is a flow diagram illustrating a method of aerosol aging andconcentrating for simulating operational conditions according to anembodiment of the invention.

IV. DETAILED DESCRIPTION

Non-limiting embodiments of the present invention are discussed indetail below. While specific configurations are discussed to provide aclear understanding, it should be understood that the disclosedconfigurations are provided for illustration purposes only. A person ofordinary skill in the art will recognize that other configurations maybe used without departing from the spirit and scope of the invention.

At least one embodiment of the invention provides a system and methodfor an aerosol centrifuge for use upstream with an aerosol aging drumapparatus. The system is suitable for continuously concentrating largequantities of aerosol in conjunction with the aerosol aging drum.

The system can facilitate experiments that examine the effects of agingand environment on the viability of chemical or biological aerosols bysimulating operational environments relevant to military and aidoperations. The system can be a modular component of an integratedmodular bioaerosol respiratory exposure system (IMBRE) and can becontrolled by the IMBRE software. The system can facilitate the exposureof animal experimental models to biological and chemical agents forpathogenesis and/or toxicity studies, and for therapeutic, vaccine,and/or prophylactic development against operationally relevant agents.

The system can include a low density fluid centrifuge for use with theaerosol aging drum to continuously concentrate aerosol prior to loadinginto the drum. In at least one embodiment, the system is used to developanimal models for biothreat agents and for in vivo studies to developmedical countermeasures against biothreat agents of military importance.The system can also be used to concentrate inhalation medicalcountermeasures.

FIGS. 1A-2 illustrate the mathematical steps used as part of designingan aerosol centrifuge according to an embodiment of the invention, wherethe size of the aerosol centrifuge is optimized to drive particles tothe outer radius (R) of the centrifuge. This is a concentrationmechanism, and the concentrated particles are drawn out at radius R.FIGS. 1D and 1E illustrate a position function derived from the terminalradial velocity of the particles derived from FIGS. 1A-1C. FIG. 1Fillustrates an aerosol apparatus having a vertical orientation andannotated with some of the variables used in FIGS. 1A-1F. FIG. 2 showsthe rotational speed (w) required for the residence time of theparticles in the centrifuge to be long enough for the particles to makeit to R, and then solves for R.

FIGS. 3 and 4 show the rotational speed (RPM) required for concentrationat various flow rates from the equation for radius R derived in FIG. 2(top and bottom graph) as a function of flow rate (F) (20 L/min and 40L/min) and centrifuge height (Height), for particles greater than 5microns in diameter.

FIGS. 5 and 6 show the rotational speed required for concentration atvarious flow rates from the equation for radius R derived in FIG. 2 (topand bottom graph) as a function of flow rate (F) (20 L/min and 40 L/min)and centrifuge height (Height), for particles greater than 2 microns indiameter. The top lines in each graph represent a height of 20 cm; themiddle lines in each graph represent a height of 50 cm; and, the bottomlines in each graph represent a height of 100 cm.

FIG. 7 illustrates a cross-sectional view of an aerosol concentratingapparatus 700 for use with an aerosol aging drum according to anembodiment of the invention. The illustrated aerosol concentratingapparatus 700 includes a metallic outer housing 710, an aerosol inlettube 720 connected to the outer housing 710, and an extraction tube 730connected to the outer housing 710. The extraction tube 730 can beconnected to the aerosol aging drum (not shown as being connected toapparatus 700). As used herein, the term “connected” includesoperationally connected, in communication with, physically connected,engaged, coupled, contacts, linked, affixed, and attached.

The apparatus 700 can also include an inner housing 740 connected to anaxle 750, where the axle 750 is connected to the outer housing 710 suchthat the axle 750 is axially centered within the outer housing 710. Theaxle 750 can be axially centered within the inner housing 740; and, theaxle 750 can be formed from porous material to allow particles to enterthe axle and leave the system. The axle 750 is illustrated in FIG. 7 ashaving porous material from the connection point with the inner housing740 to the bearing near the exhaust outlet for the axle 750. The axle750 can be connected to the distal end of the inner housing 740 and tothe outer housing 710 using sealed bearings. The outer housing 710, theinner housing 740, and/or the axle 750 can be cylindrical shaped.

In at least one embodiment, the inner housing 740 is formed from wiremesh and is adapted to spin about the axle 750 within the outer housing710 to separate aerosol particles by size. In other words, the innerhousing 740 spins with the axle 750 at the same speed. Morespecifically, aerosol particles below a first threshold size can beforced out of the aerosol concentrating apparatus 700 through the axle750; and, aerosol particles above a second threshold size can be forcedagainst an inner wall of the outer housing 710. Aerosol particlesbetween the first threshold size and a second threshold size can beforced through the inner housing 740 and collected. The inner housing740 can be adapted to spin about the axis 750 at a rate up to threethousand rotations per minute.

In at least one embodiment, the wire mesh basket spins to create aspiral motion of the air and suspended aerosol because of theirviscosity. Smaller, unwanted particles can be exhausted through theporous axle 750. Large, unwanted particles can be accelerated throughthe wire basket and deposited on the wall of the outer housing 710. Somelarger particles can fall out of the spiraling air/aerosol complex tothe bottom of the basket. Desirable particles can be accelerated throughthe wire basket and can be siphoned out of the device. The outer housing710 can be stationary to provide protection from injury from thespinning components.

FIG. 8 is a flow diagram illustrating a method for using an aerosolconcentrating apparatus for use with an aerosol aging drum (e.g., theaerosol concentrating apparatus 700) according to an embodiment of theinvention. Aerosol particles can be inserted into an outer housing ofthe aerosol concentrating apparatus through an aerosol inlet tube 720connected to the outer housing 710, 810.

In at least one embodiment, an inner housing 740 inside of the outerhousing 710 is rotated to separate the aerosol particles by size, suchthat the inner housing 740 rotates around a porous central axle 750inside of the outer housing 710, 820. The central axle 750 can alsorotate at the same speed as the inner housing 740. The rotation of theinner housing 740 can be performed continuously or in an intermittentpulse mode. The rotation of the inner housing 740 can be performed at arate of up to three thousand rotations per minute.

Aerosol particles below a first threshold size can be extracted throughthe porous central axle 750, 830. Aerosol particles above a secondthreshold size can be forced to an inner wall of the outer housing 710and/or through an aerosol extraction tube 730 connected to the outerhousing 710, 840. Aerosol particles between the first threshold size andthe second threshold size can be suspended within the inner housing 740,850. The suspended aerosol particles between the first threshold sizeand the second threshold size can be aged within the inner housing 740.

At least one embodiment of the invention includes a system having aslowly rotating drum designed to concentrate and maintain aerosolsuspended along the central axis and prevent settling. The drum can beconstructed of ultraviolet (UV) transparent material and the internaltemperature and humidity can be controlled. The aerosol can be aged orexposed to various environmental factors (e.g., temperature extremes,humidity extremes, UV light, etc.) for short or long periods of time,and then evacuated into an exposure chamber or collected for analysis todetermine the effects of aging or environmental conditions on theviability of the biological/chemical agent. The aerosol can beconcentrated by an “inverted” virtual impactor that prevents particlesfrom being evacuated from the drum by obstructing particle advectionwithin the exiting streamlines.

The system can be operated by slowly rotating the drum at low rotationalspeeds. Aerosol can be injected via the inlet port, and air can beevacuated via the inverted impactor (concentrating) nozzle toconcentrate the aerosol particles within the drum. In at least oneembodiment, once the desired aerosol concentration is reached, bothports are closed and the aerosol is aged for the desired amount of timeand exposed to the desired environmental conditions (e.g., UV light). Atthe end of the aging period, the aerosol can be evacuated into anexposure chamber or other testing apparatus through the inlet port.

Thus, the system can concentrate the aerosol, expose the aerosol toenvironmental conditions (i.e., UV light) prior to use, and exposeanimals to aerosol directly from the drum. Currently available rotatingdrums only provide the ability to age the aerosol and are not able toreach concentrations above the initial concentration of the nebulizer.

The system can allow a user to examine the effects of aging andenvironment on the viability of chemical or biological aerosols bysimulating operational environments relevant to military operations. Thesystem may facilitate the exposure of animal experimental models tobiological and chemical agents for pathogenesis/toxicity studies, andfor therapeutic/vaccine/prophylactic development against operationallyrelevant agents. The system can provide a means to study the effects oftime and environment on the properties of biological aerosols. This mayinform infectivity studies and enable users to better understand thebehavior of aerosolized biological and chemical weapons in real-worldenvironments in order to develop more effective countermeasures.

FIG. 9 illustrates a top left perspective view of a system 100 for anaerosol aging and concentrating drum for simulating operationalconditions according to an embodiment of the invention. The system 100can include a rotating drum concentrator (RDC) drum cap 1, an RDC drumcylinder 2, an RDC stand vertical frame 4, two RDC stand bases 5 (onlyone is shown), an RDC case bottom 6, two RDC case faces 7 (only one isshown), an over shaft two pass rotary union 11, two national pipe thread(NPT) couplings 13 (only one is shown), two RDC sampling tubes 16 (onlyone is labelled), a heater exchanger (heat/cool) 19, twotemperature/humidity/pressure sensors 20 (only one is shown), and aUVA/UV-b light source 21. In the system 100, the components may beconsolidated or swapped for other components.

The RDC drum cap 1 can be a stainless steel left drum face with holesfor inlet, sampling, sensor wires, etc. The holes can be axiallycentered. The RDC drum cylinder 2 can be formed from specialized glassakin to borosilicate glass and can have a high thermal conductivity aswell as UVA/UV-B transparency. The RDC stand vertical frame 4 and theRDC stand bases 5 can be formed from stainless steel and dampenvibrations caused by the concentrating procedure and drum rotation. Thecase can include the RDC case bottom 6, the RDC case faces 7, two RDCcase sides (not shown), and an RDC case top (not shown). The case can beformed from acrylic or a similar polymer and can provide a space to heatand cool the drum and aerosol as well as provide safety to the operatorfrom the rotating elements.

The over shaft two pass rotary union 11 and the NPT couplings 13 canform a rotary union providing a means of sampling and transportingelectrical signals across the rotational plane. The over shaft two passrotary union 11 and the NPT couplings 13 can be formed from stainlesssteel and corrosion/chemical resistant rolling elements. The RDCsampling tubes 16 can allow for periodic sampling of the aerosolparticles. The heater exchanger 19 can heat or cool the enclosure andthus the drum to a wide environmental temperature range; and, thetemperature/humidity/pressure sensors 20 can monitor temperatures,humidity, pressures, and UV levels inside the enclosure and drum. TheUVA/UV-b light source 21 can generate sun simulating UVA/UV-B spectrumrays. The heater exchanger 19, the temperature/humidity/pressure sensors20, and the UVA/UV-b light source 21 can be formed from corrosionresistant materials.

FIG. 10 illustrates a top view of the system 100 showing an NPT coupling13. In at least one embodiment, the RDC drum cylinder 2 can be 18.50centimeters long. FIG. 11 illustrates a front view of the system 100showing an RDC inlet 3, an RDC cone assembly 14, and an RDC vacuum valvesystem 17. FIG. 12 illustrates a left side view of the system 100; and,FIG. 13 illustrates a right side view of the system 100 showing an RDCdrum cap right 15. FIG. 14 illustrates a top right perspective view ofthe system 100. Although not shown, the system 100 can further includetwo shaft bearings and two simple single pass rotary unions.

FIGS. 15-19 illustrate the geometry of the rotating drum aerosolconcentrator according to an embodiment of the invention. The aerosolconcentrator can perform like a virtual impactor by fractionatingparticles above a design cut-point according to their inertia. Aerosolparticles entering the drum can be focused at the apex (item 2 in FIG.18) of the triangular concentrator nose. Particles with sufficientinertia can be diverted back into the core of the drum by the angularnose. In at least one embodiment, smaller particles without sufficientinertia, along with water vapor and gases, negotiate the change indirection to enter the jet nozzles shown in FIGS. 15, 16, and 17, andare removed from the drum through the exit column shown in item 1 ofFIG. 18. FIG. 19 illustrates the geometry of the rotating drum aerosolconcentrator according to an embodiment of the invention.

FIG. 20 illustrates a system 1200 for aerosol aging and concentratingfor simulating operational conditions according to an embodiment of theinvention. The system 1200 can include a rotatable drum 1210 thatmaintains the aerosol particles suspended along a central axis ofrotation of the rotatable drum 1210. This can prevent the aerosolparticles from settling on the bottom of the rotatable drum 1210. Therotatable drum 1210 can be at least partially ultraviolet lighttransparent material.

An inlet port 1220 can be connected to the rotatable drum 1210, wherethe inlet port 1220 can receive aerosol particles. A nozzle 1230connected to the rotatable drum 1210 can expel air from the rotatabledrum 1210 to concentrate the aerosol particles within the rotatable drum1210.

An exposure device 1240 can expose the aerosol particles within therotatable drum 1210 to one or environmental conditions. For instance,the exposure device 1240 can expose the aerosol particles to ultravioletlight, heat, cold, high humidity, and/or low humidity. An increase ordecrease in temperature can be induced using a heat exchanger around therotatable drum 1210. In at least one embodiment, humidity is changedwith a humidifying component (e.g., an in-line dryer and/or in-linehumidification device) that is placed upstream of the drum in theaerosol line. A quad track diffusion dryer can be placed in line toreduce the humidity. The system 1200 can also include a thermometerand/or a humidity sensor in the rotatable drum 1210.

An outlet port 1250 connected to the rotatable drum 1210 can evacuatethe aerosol particles directly from the rotatable drum 1210 into anexposure chamber and/or a testing apparatus. The system 1200 can alsoinclude an inverted virtual impactor that concentrates the aerosolparticles and prevents the aerosol particles from being evacuated fromthe rotatable drum 1210 by obstructing particle advection within exitingstream lines.

FIG. 21 is a flow diagram illustrating a method for aerosol aging andconcentrating for simulating operational conditions according to anembodiment of the invention (e.g., using the system 1200). Aerosolparticles can be injected into an inlet port of a rotating drum 1310.Air can be expelled from the rotating drum via a nozzle to concentratethe aerosol particles within the rotating drum 1320. The inlet port andthe nozzle can be closed when the desired aerosol concentration isreached 1330.

The aerosol particles can be exposed to one or more environmentalconditions, such as, for example ultraviolet light, heat (e.g., aboveambient temperature), cold (e.g., below ambient temperature), highhumidity (e.g., above ambient humidity), and low humidity (e.g., belowambient humidity) 1340. In at least one embodiment, the rotating drum isformed from ultraviolet light transparent material and the rotating drummaintains the aerosol particles suspended along a central axis ofrotation of the rotating drum to prevent the aerosol particles fromsettling on a bottom of the rotating drum. This can be accomplished viacentripetal force. In at least one embodiment, the aerosol particles areconcentrated by an inverted virtual impactor that prevents the aerosolparticles from being evacuated from the drum by obstructing particleadvection within exiting streamlines. The aerosol particles can beevacuated directly from the rotating drum into an exposure chamberand/or a testing apparatus after an aging period 1350.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the root terms “include”and/or “have”, when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of at least oneother feature, integer, step, operation, element, component, and/orgroups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans plus function elements in the claims below are intended to includeany structure, or material, for performing the function in combinationwith other claimed elements as specifically claimed. The description ofthe present invention has been presented for purposes of illustrationand description, but is not intended to be exhaustive or limited to theinvention in the form disclosed. Many modifications and variations willbe apparent to those of ordinary skill in the art without departing fromthe scope and spirit of the invention. The embodiment was chosen anddescribed in order to best explain the principles of the invention andthe practical application, and to enable others of ordinary skill in theart to understand the invention for various embodiments with variousmodifications as are suited to the particular use contemplated.

What is claimed is:
 1. A system for aerosol aging and concentrating,said system comprising: a case; a stand within said case; a rotatablecylinder drum mounted on said stand, said drum having a first drum cap,a second drum cap, and a cylindrical wall connecting said first drum capand said second drum cap, wherein said cylindrical wall includestransparent material; an inlet port passing through said first drum capat substantially an axle center of said rotatable drum; an impactormounted on said second drum cap and facing said inlet port, saidimpactor having a triangular concentrator nose and nozzles near aperipheral edge of said nose; a vacuum valve system connected to saidnozzles; and an ultraviolet light source facing said rotatable drumand/or a heat exchanger within said case, said heat exchanger configuredto heat or cool an interior of said case.
 2. The system according toclaim 1, wherein said impactor further includes a base on which the noseis mounted and the base is mounted on said second drum cap, said vacuumvalve system passing through said base; and said nose having threedifferent curvatures from a tip to the peripheral edge with a curvatureof said nose at the peripheral edge approaching a plane perpendicular tothe axial center of said rotatable drum.
 3. The system according toclaim 1, wherein said impactor further includes a base on which the noseis mounted and the base is mounted on said second drum cap, said vacuumvalve system passing through said base; and said nose flares out from atip to the peripheral edge.
 4. The system according to claim 1, whereinsaid impactor further includes a base on which the nose is mounted andthe base is mounted on said second drum cap, said vacuum valve systempassing through said base; and a ratio of a height of said nose to saidheight of said nose and said base is 3 to
 7. 5. The system according toclaim 1, wherein said nose transitions from a steeper slope at a tip toa shallower slope at the peripheral edge.
 6. The system according toclaim 1, further comprising sampling tubes passing through said firstdrum cap.
 7. The system according to claim 1, further comprising: anin-line dryer and/or an in-line humidification device, and a humiditysensor.
 8. A system for aerosol aging and concentrating for simulatingoperational conditions on aerosol particles, said system comprising: arotatable drum; an inlet port connected to said rotatable drum, saidinlet port configured to receive aerosol particles; a nozzle connectedto said rotatable drum, said nozzle configured to expel air from therotatable drum to concentrate the aerosol particles within saidrotatable drum; an exposure device configured to expose the aerosolparticles present in said rotatable drum to at least one environmentalcondition; an outlet port connected to said rotatable drum, said outletport configured to evacuate the aerosol particles directly from saidrotatable drum into an exposure chamber and/or a testing apparatus. 9.The system according to claim 8, further comprising an inverted virtualimpactor that concentrates the aerosol particles and prevents theaerosol particles from being evacuated from said rotatable drum byobstructing particle advection within exiting stream lines.
 10. Thesystem according to claim 8, wherein said rotatable drum includesultraviolet light transparent material.
 11. The system according toclaim 10, wherein said exposure device includes an ultraviolet lightsource facing said rotatable drum and configured to exposes contents ofsaid rotatable drum to ultraviolet light.
 12. The system according toclaim 8, further comprising a case housing said rotatable drum, saidinlet port, said nozzle, said exposure device, and said outlet port; andwherein said exposure device includes a heater exchanger configured toheat or cool an interior of said case.
 13. The system according to claim12, further comprising a thermometer in said rotatable drum.
 14. Thesystem according to claim 8, wherein said exposure device includes anin-line dryer connected to said inlet port, said in-line dryerconfigured to expose the aerosol particles to low humidity.
 15. Thesystem according to claim 14, further comprising a humidity sensor insaid rotatable drum.
 16. The system according to claim 8, wherein saidexposure device includes an in-line humidification device, said in-linehumidification device configured to expose the aerosol particles to highhumidity.
 17. The system according to claim 8, wherein said exposuredevice exposes the aerosol particles present in said rotatable drum toultraviolet light, heat, cold, high humidity, and low humidity.
 18. Thesystem according to claim 8, wherein said rotatable drum maintains theaerosol particles suspended along a central axis of rotation of saidrotatable drum to prevent the aerosol particles from settling on abottom of said rotatable drum.
 19. A method for aerosol aging andconcentrating for simulating operational conditions, said methodcomprising: injecting aerosol particles into an inlet port of a rotatingdrum; expelling air from the rotating drum via a nozzle to concentratethe aerosol particles within the drum; closing the inlet port and thenozzle when a desired aerosol concentration is reached; exposing theaerosol particles to at least one environmental condition; evacuatingthe aerosol particles from the rotating drum after an aging period, theaerosol particles being evacuated directly from the rotating drum intoeither an exposure chamber or a testing apparatus.
 20. The methodaccording to claim 19, wherein said exposing of the aerosol particles toat least one environmental condition includes exposing the aerosolparticles to ultraviolet light, heat, cold, high humidity, and lowhumidity.